Welding machine



July 5, 1932. A. LUTz WELDING MACHINE 2 sheets-sheet 1 Filed Feb. ll, 1931 July 5, 1932. G. A. LUTz WELDING MACHINE Fi'led Feb. 1 1, 1931 2 Sheets-Sheet 2 R Y mz Mw N R wm WL Tm H a? em G Patented July 5, 1932 UNITED STATES PATENT OFFICE GEORGE A. LUTZ, 0F CBANFOBD, NEW JERSEY, ASSIGNOR T0 AMERICAN CIRCULAR LOOM COMPANY, INC., F DOVER, DELAWARE, A CORPORATION 0F DELAWARE WELDING MACHINE application fuga February 11, 1931. serial No. 514,945.

In\` some welding machines .spaced electrodes are secured together for unitary rotation; in contact with metal to be Welded, such as tubular metal blanks. Where the tubular` blanks are butt-Welded the diameter ofthe electrodes may be similar, and where the tubular blanks are lap-,welded one electrode must be of greater diameterthan the other electrode when they are radially disposed with respect to a tubular blank in order that both electrodes may contact with surfaces ofy times attained with consequent increase of g current consumption.

The object of my invention is to provide an,l electrical Welding machine or transformer in which spaced electrodes of different, diameters may be used, as in lap-welding of tubular 80 blanks, and in which the electrodes will be independently rotative so that neither electrode will influence the rotation of the other,

whereby each electrode may rotate in contact withja corresponding portion of the tubular blank individually to avoid sliding contact therewith to reduce wear on the corresponding electrode due to its contact with the blank.

In carrying out my invention as illustrated I provi-de a transformer having spaced rotative electrodes in electrical circuit With the secondary of the transformer, yone of said electrodes being secured to one portion of the secondary and the other electrode being rotatively connected with another portion of the secondary and free to rotate relatively thereto, whereby each electrode may contact with a given portion of a metal blank on opposite sides of a lap or seam to be Welded 5U and each electrode may rotate independently of the other asthe blank is traversed in contact with said electrodes.

My invention also comprises novel details of improvement that will be more fully hereinafter said further and then pointed out in the claims.

Reference is to be had to the accompanying drawings in which, Fig. 1 is a side view artly in section, illustrating a rotary trans ormer embodying my invention; l

Fig. 2 is a sectional detail substantially on the line 2, 2 in Figure 1. 1

Fig. 3 is a section on line 3, 3 in Figure 2.

Fig. 4 is a detail plan view of Figure 3.

Fig. 5 is a sectional detail of a modifica-- tion, and

Fig. 6 is a Jface view of a unitary electrode.

Similar numerals of reference indicate corresponding parts in the several views.

improvements are illustrated in connectlon with a transformer of the rotary type., such asset forth in Letters Patent to Snodrass and Hunter No. 1,478,262, granted December 18, 1923. The secondary of the transformer is indicated at 1, comprising a rotative body or shell having a face plate 2 electrically connected thereto and which may be integral with a tubular axial portion 3 that extends laterally from one side of the shell through and beyond the latter, andan outer cylindrical part 4 is spaced from the axial portion 3 and extends from the face plate 2. Ventilating openings 5 may be provided in the cylindrical part 4. Said parts may be cast in a single piece of metal. The opposite side of the secondary body or shell is provided' with a plate 6, which may be secured to the annular part. 4 by any desired means, such as by screw-threads at 7. The plate 6 has a bore at 6a of greater diameter than the portion 3 of the secondary to fit around and out of contact with the latter for insulating parts 3 and 6 from each other. At 8 is an annular electrode which may be made in a 'series of segments 8a having radial edges 8b, preferably set in contact, as illustrated in Figure 2, or said electrode may be made in a single annular piece, as illustrated in Figure 6. The electrode 8 is 10 mounted upon and adapted to rotate independently with respect to a portion of the secondary of the transformer, being .shown mounted upon the axially extended portion 3a of the secondary and in circuit therewith. I have illustrated a metal sleeve 9 rotatively mounted on and in contact with the axial portion 3a of the secondary, and upon said sleeve 9 is mounted a metal support 10 to make electrical contact with the sleeve 9. The sleeve 9 may be secured on the axial portion 3a by any desired means, such as by shrinkage or screws.

.The electrode 8 is detachably connected with the support 10/and in electrical contact therewith. A ring 11 surrounds a portion of the support 10 and is detachably secured thereto. I have shown screws 12 passing through holes 13 in the ring 11 and meshing in threaded apertures 14 in support 10 for detachably securing the rin to said support. rlhe electrode is shown provided with recesses 15 into which plugs or studs 16 enter, which plugs extend through holes in the ring 11' or securing the electrode 8 upon an annular seat 10a of the support 10. The plugs are shown tapered at their inner ends to engage the bottom walls of the recesses 15 to force the electrode into contact with the support 10. The support 10 is shown provided with an angularly disposed face 10b against which a corresponding angular face 8 of the electrode is adapted to bear, whereby said faces meet in a wedge-like manner for securing the electrode electrically aga-inst the support 10. By making the electrode 8 in several segments, as illustrated in Figure 2, the electrode segments may be readily removed and replaced, which will be found particularly' advantageous when the electrode is used for welding pipe or tubes of heavy gauge Walls and large diameters. If preferred, however, electrode 8 may be in a single piece of metal adapted to be secured to the support 10 in manner described by utilizing the ring 11 and the plugs 16.

In Figure 5, the recesses 15 are shown tapering to receive the correspondingly tapered ends of the plugs 16, whereby the electrode segments, or the unitary electrode, may be positively secured by said lugs.

In order to provide goo electrical contact between the support 10 and the sleeve 9any desired number of brushes 17, of any wellknoWn material, such as carbon or wire mesh, are slidably located in bores 18 in the support 10 to contact with the sleeve 9 (Figs. 1 and 3). Said brushes are normally pressed against sleeve 9 by springs 19 located in said bores and bearing against said brush and4 against threaded plugs 20 in said bores. Said brushes may be removed and replaced conveniently, as desired, by means of the construction described. "The sleeve 9 is replaceable to accommodate for wear of the brushes 17, as distinguished from causing the brushes to contact with the axial portion 3a.

An electrode 21 is electrically connected with a second side of the secondary, being shown in electrical connection with the plate 6 of the secondary. Electrode 21 may be similar to the electrode 8, that is to say, it may comprise several sections, or be in a single piece, as previously described. I have shown a ring 22 provided with screws 28, to secure said ring to the plate 6 in manner described with respect to the screws 12, and plugs 24 carried by the ring 22 to enter recesses 25 in the electrode 21, in manner described with respect to the electrode 8. The plate 6 is shown provided with an extension 6 upon which the electrode 21 and the ring 22 are applied. The electrode 21 is shown provided with an inclined face 26 engaging a correspondingly inclined face 27 projecting from the part 6', whereby said electrode is secured to said face 27. The support 10 and the projecting portion 6 of the secondary are spaced apart and the electrodes 8 and 21 are also spaced apart, insulation 28 of any suitable character preferably being interposed between the parts 10, 6', Sand 21.

I have illustrated the part 6 of the secondary in the form of a jacket extending from the plate 6 adapted to contain cooling water 'for the electrode 21. I have also illustrated a hollow jacket 29 upon the extended axial portion 3a of the secondary adapted to contain cooling water, the said jacket 29 being in Contact with the support 10, as illustrated in Figure 1. A nut 30, on extended part 3a, is adapted to bearing against jacket 29 to retain thelatter in position. The flange of sleeve 9 and the nut 30 retain the parts 10 and 29 from sliding axially.

Cooling water may be supplied through a pipe 31 to a tube 32 and thence into jacket 6, and from said jacket through a tube 33 to a water space 34, from which a tube 35 extends and communicates with jacket 29, and a tube 36 provides communication between jacket 29 and an outlet passage 37, plugs 38 and 39 closing the passage. The details of the cooling arrangements described are substantially the same as those set forth in my application Serial No. 441,784 filed April 5, 1930.

The secondary is shown secured to a member 40 carried by shaft 25 that supports the' secondary, the secondary and the member 40 being shown insulated at 41 and secured together by screws 42 insulated from said member. The primary 43 of the transformer ,is shown comprising a core 43a and winding j 4322 within the chamber 2a of the secondary body or shell. The terminals of said primary are connected to collector rings 44 and 45 that are carried by and insulated 'from the body 2 insulated screws 46 connecting the collector rings to said body. Alternating current is led to the collector rings from any desired source by brushes 47. The member 40, the collector rings, and the brushes,maybe similar to corresponding parts set forth in the aforesaid Letters Patent. The shaft may be journaled in a frame 48 in any desired way. As illustrated the secondary body orshell 2 and its axial extension 3a are mountedupon a tube 49 within lthe bore of the parts 3 and 3a. The tube 49 is mounted upon an insulating sleeve 50 located in said tube and upon shaft 25.

At A is indicated .a tubular metal blank whose margin or edge portions are to be welded together. The tube may be guided for contact with the electrodes 8 and 21 in any .desired or well-known way, such as by means of rollers 51 suitably spaced apart and car- 20 ried by studs or shafts 52, any suitable or well-known means being provided for traversing the blank A along the electrodes at desired speed. In the example illustrated in Figure 1, the marginal portions a and a are lapped and the electrodes bear upon the blank on opposite sides of the joint at said lap, whereby when electric current flows from the secondary through said electrodes it will trav erse the blank at the lap for heating the portions a and a to a welding heat for welding said lapped portions together. Both of the electrodes will rotate by reason of contactV with the tubular blank as the latter travels. By reason of the lapping of the marginal portions of the blank the radius of the inset portion a is less than the radius of the portion a and the diameter of the e1ectrode`8 1s greater, to contact with the portion a of the blank than the diameter of the electrode 2l that contacts with the outer portion a of the blank. Since the electrode 8 may rotate independently or individually with respect to the rotation of the electrode 21, (which rotates at the same speed as the transformer), each electrode may .rotate in contact with the corresponding portion'of the blank A without regard to the'rotation of the other electrode, since the electrodes have a common axis and are spaced apart relatively to the lap or joint of the metal blank between them. Said electrodes may rotate at different surface speeds, each electrode rotating individually with respect `to the other according tothe diameter of the electrode, whereby one electrode does not control the rotation of the other and thereby `slippage of one electrode in contact with the metal blank caused by rotation of the other electrode-does not occur as does occur where tworotary electrodes of different diaineters are secured together to rotate as a unit in well knowntypes of lap-welding machinos. By the means described Wear upon the surface of each electrode will be in conformity with its operation as an independent electrode, and undue wear on the contacting surface of the electrode 8 is eliminated.

While I have illustrated my improvement in connection with a transformer of the rotary type, in which the primary and secon ary rotate together for supplying current to the individually operative electrodes on a common axis, it will be understood that current may be supplied to said electrodes in any other well-known or desired way.

Although I have illustrated my improved electrodes individually rotative on a common axis one electrode having a greater diameter than the other electrode, it will be understood that spaced electrodes on a common axisvmay have substantially the same diameter with the advantage that neither electrode will control the rotation of the other, whereby inequality in the stock to be welded will not affect the rotation of the electrode not sub jected to such inequalities, which might oc cur were the two electrodes secured together to rotate as a unit, such as in butt-welding of heavy gage stock.

Having now described my invention what I claim is v 1. An electric welding machine comprisingV an axial portion, an electrode mounted thereon andV insulated therefrom, a second electrode spaced from the first named electrode and mounted on and 'in electrical circuit with s'aid axial portion, and means to supply said electrodes with electric current, said electrodes being rotative individually one with respect to the other to rotate at a different speed with respect to the speed of the latter.

2. An electric welding machine as set forth in claim 1 in which one of the electrodes is of greater diameter than the other electrode.

3. An electric welding machine comprising a transformer having a secondary body provided with an axial portion, an electrode in electrical connection with a portion of said body, a second electrode spaced from the first named electrode and mounted to rotate independently thereof, said electrodes having their axes common with the axis of said axial f' secondary body provided with an axial por-v tion, an electrode secured to and in electrical connection with one portion of said body, a second electrode spaced from the first named electrode and mounted to rotate upon said axial portion, and in electrical connection therewith.

6. An electric welding machine as set forth with said support and in claim 5, in which one of the electrodes is of greater diameter than the other electrode to rotate at a different speed with respect tothe speed of the latter.

7 An electric Welding machine having an electrode comprising a plurality of annularly disposed segments, a rotative support for said segments, a ring secured to the support, and studs carried by the ring, the segments having recesses to receive the studs to detachably secure said segments to said support.

8. An electric Welding machine having an electrode comprising a plurality of annularly disposed segments, a rotative support for said segments, a ring secured to said support, and tapering studs carried by said ring, the segments having recesses to receive the studs for detachably securing the segments on said support.

9. An electriewelding machine comprising a transformer secondary body provided with an axial portion, an electrode in electrical connection with said body, a support rotatively mounted on said axial portion, a second electrode carried by said support in electrical connection therewith and spaced from the rst named electrode, and brushes connected electrically operative with said ax1al portion.

10. An electric Welding machine as set forth in claim 9, provided with a sleeve mounted on the axial portion and carrying sald support, said brushes being in contact with said sleeve.

GEORGE A. LUTZ. 

